package com.lzx.gateway.filters;

import com.lzx.gateway.config.AuthProperties;
import com.lzx.gateway.util.JwtTool;
import lombok.RequiredArgsConstructor;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.util.AntPathMatcher;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.List;

@Component
@RequiredArgsConstructor
public class AuthGlobalFilter implements GlobalFilter, Ordered {

    private final AuthProperties authProperties;
    private final JwtTool jwtTool;


    private final AntPathMatcher antPathMatcher = new AntPathMatcher();

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1.去获取request对象
        ServerHttpRequest request = exchange.getRequest();

        //2.判断是否需要进行拦截，不需要则放行
        if (isExclude(request.getPath().toString())) {
            // 放行
            return chain.filter(exchange);
        }

        //3.获取token
        String token = null;
        List<String> headers = request.getHeaders().get("authorization");
        if (headers != null && !headers.isEmpty()) {
            token = headers.get(0);
        }

        //4.校验并解析token
        Long userId = null;
        try {
            userId = jwtTool.parseToken(token);
        } catch (Exception e) {
            // 如果解析失败，终止请求，返回状态码401
            ServerHttpResponse response = exchange.getResponse();
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();
        }

        // 5.将用户信息保存到请求头中，向下传递
        String userInfo = userId.toString();
        System.out.println("userId=" + userId+",userInfo="+userInfo);
        ServerWebExchange newExchange = exchange.mutate()
                                          .request(builder -> builder.header("user-info", userInfo))
                                          .build();

        //6.放行
        return chain.filter(newExchange);
    }

    private boolean isExclude(String path) {
        for (String pathPattern : authProperties.getExcludePaths()) {
            if (antPathMatcher.match(pathPattern,path)) {
                return true;
            }
        }
        return false;
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
